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Full text of "Text Book Of Mechanical Engineering"

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Vertical Milling

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table. They are fixed in the centre of the swivelling table, and
will transmit the feed motion with steadiness, even when the
table is swivelled up to 45, say for cutting spiral mills, twist
drills, &c. By moving the hand lever y the mitre wheel w may
be drawn out of gear, and the cross feed given by hand, if
desired, a catch z ensuring the contact of the wheels when in gear.
The longitudinal feed from screw a is rather a setting motion,
there being few cases where other tban a cross feed is desired.

The handle b is to raise or lower the table, which it does by
turning the screw e through the medium of the worm gear d.

Other forms of machine are Vertical Milling Machines and
Profiling Machines. In the former the cutter spindle is vertical,
and a circular feed, as well as traverse, is given to the table. The
latter is a smaller tool, where a vertical mill is traversed by a hand
lever so as to accommodate itself to intricate forms. Good lubrica-,
tion is necessary for all mills, and should be supplied under pressure
from a small pump. (See also pp. 752, 811, 1020, and 1025.)

CUT Tf/l

. /(PP.

Dividing Head.  When milling teeth of wheels, cutters, rimers,
&c., the work is supported in centres shewn in Fig. 189, which
are fastened to a small bed and bolted to the machine table.
The wheel to be cut is fixed on a mandrel, and held in position